The present invention is directed generally to an interlock system for preventing connection or disconnection of an electrical line or cord to an electronic module while the module is in a power-on, current-drawing state.
Applying power to, or removing power from, an electronic module while in the power-on or current-drawing state is a problem long recognized in the art (see, e.g., U.S. Pat. No. 3,919,507 to Middleton, Jr., dated Nov. 11, 1975). Typically, the problem is encountered when the module is inserted in or removed from a larger system. Removable electronic modules, when inserted or removed, can, if in the power-on state, can create power transients that may damage electronic circuitry contained in the module, or create problems in the system into/from which the module is being inserted/removed.
Such problems have been encountered, and addressed in connection with removable electronic modules having blind matable connections. Solutions include latch handles or insertion/extraction mechanisms mounted in cooperative relation to a power on/off switch, forming an interlock mechanism that is operable to permit insertion or removal of the module only if the module is in a power-off, non-current-drawing state. Examples of such mechanisms include U.S. Pat. Nos. 4,777,332, 4,885,436, and 4,931,907.
These interlock mechanisms are, however, directed to insuring that the electronic module is in a power-off state when inserting or removing the module from a larger system. They do not provide any protection for electronic modules of the type that receive a removable electrical and/or power cord connection.
Accordingly, there is a need for an interlock system to prevent connection or removal of a power cord to an electronic module while the module is in a power on state.